Disk storage with modifiable data management function

ABSTRACT

A disk storage device comprising; a disk controller for accessing a disk storage medium to read/write data thereon, an object management program for converting a control command containing an object identifier received through a network interface into a control command containing physical address information of the disk storage medium and for feeding the thus converted control command to the disk controller, an object management modification program for modifying a function of the object management program in response to a modification request message received through the network interface, and a processor for carrying out these programs.

BACKGROUND OF THE INVENTION

[0001] (1) Field of the Invention

[0002] The present invention relates to a disk storage device, and moreparticularly to a disk storage device having a modifiable datamanagement function.

[0003] (2) Description of the Related Art

[0004] Conventionally, a magnetic disk storage device is provided withjust simple functional features, such as a function for managing data ona fixed-block-size basis, due to limitations in hardware configuration.

[0005] In the SCSI (Small Computer System Interface) scheme which wasdeveloped by the ANSI (American National Standard Institute) and hasbeen in widespread use for interfacing between a magnetic disk storagedevice and a computer, data input/output is carried out in units ofblocks (sectors) each having a physically predetermined size, not indata structural units corresponding to logical data aggregates such asfiles or tables. Since the SCSI is applicable just to a relatively lowlevel of interfacing, it is required to provide a file system or adatabase management system to be carried out on a host computer (or diskserver) directly connected with the conventional magnetic disk storagedevice in the case of implementation of high-level interfacing capableof transferring logical data blocks such as files or tables, forexample. Further, since the conventional magnetic disk storage device isnot provided with an interface mechanism for direct connection to acommunication network, intervention of the host computer directlyconnected with the magnetic disk storage device is required for anapplication program running on another computer to input data to aremote magnetic disk storage device or to output data therefrom.

[0006] In the background of rapid advances in hardware technologies andtrends toward lower cost of hardware, an NASD (Network-Attached SecureDisk) has recently been proposed by G. Gibson of Carnegie-MellonUniversity (Proceedings of the 8th ASPLOS Conference, 1998), which is amagnetic disk storage device having a communication network connectioninterface mechanism that enables direct input/output of magnetic diskdata through a remote computer without intervention of a host computer.In addition to the network connection interface mechanism, the NASD isalso provided with a function for managing stored data so as to enableaccessing each logical aggregate structure of data such as a file, forexample.

[0007] Examined hereinbelow is the technique of OLAP (Online AnalyticalProcessing) for data mining and decision-making system applications thatare expected to proliferate in the near future. In OLAP for market trendforecasting, for example, business data querying processing is carriedout frequently to find out any data meeting a certain condition among alarge amount of data. In a conventional data query system, all thebusiness data under search examination are read out sequentially frommagnetic disk storage, and a computer makes a judgment whether or noteach data meets a specified search condition to find out desired data.Therefore, most data not meeting the specified search condition aretransferred to the computer uselessly in consequence. In this situation,if only the data meeting the specified search condition can betransferred to the computer by feeding the specified search condition tothe magnetic disk storage, the amount of data transferred from themagnetic disk storage to the computer is decreased significantly toenable substantial reduction in work load on the computer.

[0008] It is possible to speed up data analysis and image processing byproviding magnetic disk storage with functions for supporting OLAP andimage processing, which has been suggested in evaluation experimentsconducted at Carnegie-Mellon University (Proceedings of the 24th VLDBConference, 1998) and University of California—Santa Barbara(Proceedings of the 8th ASPLOS Conference, 1998).

[0009] The above-noted NASD has been proposed since it has becomecostwise feasible to incorporate a hardware function for processing datain units of logical data into magnetic disk storage thanks to rapidadvances in hardware technologies accompanied with substantial reductionin cost of hardware. As expected at present, further progress inhardware technologies will still reduce hardware cost, making itpossible to provide magnetic disk storage with more advanced functions.

[0010] However, merely fixed functionality is provided in the NASD. Forexample, in the NASD, it is not allowed to discretionarily add anyfunction (object management function) for managing stored data in accessunits of logical data structures such as directories or folders(hereinafter referred to as objects) or to arbitrarily modify an objectmanagement function in part. Further, while the performance of theconventional magnetic disk storage device can be improved substantiallyusing a data caching function, the NASD does not allow a user to modifyany data management attribute concerning the data caching function, forexample, or to add such an extended function as an OLAP supportfunction.

SUMMARY OF THE INVENTION

[0011] It is therefore an object of the present invention to provide adisk storage device having a modifiable object management function.

[0012] Another object of the present invention is to provide a diskstorage device which allows a user to specify and modify fileorganization, object management attributes, and extended functionality.

[0013] In accomplishing these objects of the present invention andaccording to one aspect thereof, there is provided a disk storage devicecomprising: a disk storage medium; a network interface; a diskcontroller having an object management function in which a high-levelread/write command specified for an access target using an objectidentifier received through the network interface is converted into alow-level read/write command containing physical address information ofthe disk storage medium for making access to the disk storage medium;and object management modification means for modifying the objectmanagement function in response to a modification request messagereceived through the network interface.

[0014] According to another aspect of the present invention, there isprovided a disk storage device comprising: a disk storage medium, a diskcontroller for accessing the disk storage medium to read/write datathereon; an interface for connecting the disk storage device to anetwork; object management means for converting a control commandcontaining an object identifier received through the interface into acontrol command containing physical address information of the diskstorage medium and for feeding the thus converted control command to thedisk controller; and object management modification means for modifyinga function of the object management means in response to a modificationrequest message received through the interface.

[0015] More particularly, according to the present invention, themodification request message contains at least one of parametersconcerning file organization, data management attributes and dataprocessing in correspondence with each partition identifier, and theobject management modification means modifies at least one of functionsconcerning file organization, data management attributes and dataprocessing, which are provided in the object management means, accordingto the parameter contained in the modification request message.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a diagram showing an embodiment of a computer networkincluding a disk storage device according to the present invention;

[0017]FIG. 2 is a block diagram showing an embodiment of a hardwareconfiguration of the disk storage device according to the presentinvention;

[0018]FIG. 3 is a diagram showing a software configuration arranged fordisk storage device 100 and terminal device 130 according to the presentinvention;

[0019]FIG. 4 is a diagram showing a format for a modification requestmessage 400 to be issued from the terminal device to the disk storagedevice;

[0020]FIG. 5 is a diagram showing a format for a reply message 410 to besent from the disk storage device to the terminal device;

[0021]FIG. 6 is a diagram showing a format for a management table 330provided in the disk storage device;

[0022]FIG. 7 is a diagram showing details of a partition configurationfield 333 in the management table 330;

[0023]FIG. 8 is a diagram showing details of an object organizationparameter field 334 in the management table 330;

[0024]FIG. 9 is a diagram showing details of an object managementattribute parameter field 335 in the management table 330;

[0025]FIG. 10 is a diagram showing details of an “extended function ofobject management” parameter field 336 in the management table 330;

[0026]FIG. 11 is a diagram showing a procedure for communication betweena request program 420 to be executed on the terminal device and amodification program 320 to be executed on the disk storage device;

[0027]FIG. 12 is a flowchart showing the request program 420 to beexecuted on the terminal device;

[0028]FIG. 13 is a flowchart showing the modification program 320 to beexecuted on the disk storage device;

[0029]FIG. 14 is a flowchart showing details of authentication step 710in the modification program 320;

[0030]FIG. 15 is a flowchart showing details of object managementmodification step 800 in the modification program 320;

[0031]FIG. 16 is a diagram showing a format for a control command 440 tobe sent from the terminal device to the disk storage device; and

[0032]FIG. 17 is a flowchart showing an object management program 350 tobe executed on the disk storage device in response to the controlcommand 440.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] Referring to FIG. 1, there is shown an embodiment of a computernetwork which is so configured as to include a disk storage deviceaccording to the present invention.

[0034] The computer network comprises magnetic disk storage devices 100(100A, 100B, 100C) each containing a plurality of objects correspondingto logical data structural units such as files, tables and records,computers including servers 130A and terminals 130B which act asrequesters for object management modification, and a network 110 forconnecting these disk storage devices and computers. The network 100 isconnected with another computer network or communication network througha gateway 140, for example.

[0035] In this exemplary computer network, an object managementmodification requester 130 is typically a server computer, a clientterminal computer, a host computer, or an application program to be runthereon. In a special case, a magnetic disk storage device or the likestorage device where an application program is stored may also act asone of the object management modification requesters 130.

[0036] Referring to FIG. 2, there is shown a preferred embodiment of ahardware configuration of the magnetic disk storage device 100.

[0037] The magnetic disk storage device 100 in accordance with thepresent invention comprises, a magnetic disk 101, a disk controller 102which accesses the magnetic disk 101 for reading/writing data thereon, aprocessor 103, a memory 200 for storing such programs as an objectmanagement program 350 and an object management modification program 320to be described later, a data memory 104 for providing a buffer memoryarea where data to be read/written is buffered and for forming a varietyof tables, a network interface 105 for connection with the network 110,and an internal bus 106.

[0038] The processor 103 carries out the object management program 350,whereby a high-level file control command given by a user through thenetwork 110 and the network interface 105 is converted into a low-levelcontrol command that is acceptable by the disk controller 102, e.g., aSCSI-defined low-level control command. Further, in response to anobject management modification request given by the user through thenetwork 110 and the network interface 105, the processor 103 carries outthe object management modification program 320 to modify a function ofthe object management program 350.

[0039] While the processor 103 arranged separately from the diskcontroller 102 is used to carry out the object management program 350and the object management modification program 320 in the presentembodiment, there may also be provided such an arrangement that theseprograms are carried out by a processor incorporated in the diskcontroller 102.

[0040] Referring to FIG. 3, there is shown a software configurationarranged for the object management modification requester 130 and themagnetic disk storage device 100.

[0041] The object management modification requester 130 is provided witha request program 420 for object management modification which issues arequest message 400 for object management modification to the magneticdisk storage device 100 and which receives a reply message 410 from themagnetic disk storage device, and the object management modificationrequester 130 is also provided with a management table 430 which isupdated according to the reply message 410. An object I/O command 440for reading/writing data on the magnetic disk 101 is issued by anotherapplication program for use on an ordinary computer, not by the requestprogram 420 mentioned above.

[0042] In the program memory 200 of the magnetic disk storage device100, there are contained an object management program 350, an objectmanagement modification program 320 which modifies a function of theobject management program 350 according to a request message 300(equivalent to the request message 400) received through the network 110and which outputs a reply message 310 for indicating the results ofmodification, a management table 330, a variety of component programs340 used by the object management program 350, an object managementtable 355 used by the object management program 350, and anauthentication table 370 which is referenced by the object managementmodification program 320. Reference numeral 360 in FIG. 3 indicates abuffer memory which is provided on the data memory 104 for temporarilystoring data to be read/written.

[0043] The object management modification program 320 and the objectmanagement program 350 are stored on the magnetic disk 101. When powerto the magnetic disk storage device 100 is turned on, these programs areautomatically loaded from the magnetic disk 101 to the program memory200 for execution.

[0044] To the magnetic disk storage device 100, the object managementmodification requester 130 issues the request message indicating arequest for modifying (or initially setting up) a parameter concerningobject organization (file organization), data management attributes orobject management extended functionality.

[0045] In the present embodiment, a data management attributerepresents, for example, a buffer size for temporarily storing data tobe read/written on the magnetic disk, or a specifier for determiningwhether the buffer size is to be invariable or variable. In objectmanagement functional extension, any special function other than anordinary data read/write function may be added, for example, a functionfor detecting an edge of an image in image data read out of the magneticdisk prior to transmission to the requester, a function for eliminatingnoise from image data, or a function for selection in OLAP may be added.

[0046] Referring to FIG. 4, there is shown a format for the requestmessage 400.

[0047] The request message 400 comprises a requester ID 401 foridentifying a source of request (object management modificationrequester), a request number 402, a type-of-modification code 403, and aparameter field 404 for indicating requested items.

[0048] The requester ID 401, for example, contains a combination of anIP address and a port number; the IP address indicates a location of acomputer on which a requester application program is run, and the portnumber indicates a port used by the requester application program. Theparameter field 404 contains a field 404A for indicating a partition IDdefined for a storage area on the magnetic disk 101, a field 404B forindicating object organization, a field 404C for indicating an objectmanagement attribute, and a field 404D for indicating extension ofobject management functionality.

[0049] Referring to FIG. 5, there is shown a format for the replymessage 410 for indicating the results of processing by the objectmanagement modification program 320. The reply message 310 has the sameformat as that of the reply message 410. The reply message 410 containsa requester ID 411, a request number 412, and information on the resultsof processing 413.

[0050] Referring to FIG. 6, there is shown a structure of the managementtable 330 used for defining operations of the object management program350. The management table 330 comprises a hardware specification table330A and a software specification table 330B, and the contents thereofare modified by the object management modification program 320.

[0051] The hardware specification table 330A, for example, contains afield 331 for indicating a type code of the processor 103, a field 332for indicating a capacity of the memory 200 incorporated in the magneticdisk storage device 100, and a field 333 for indicating a partitionconfiguration of the magnetic disk medium 101. These fields are providedto indicate useful reference information for selection in objectmanagement modification.

[0052] The software specification table 330B contains a parameter table334 concerning object organization, a parameter table 335 concerningobject management attributes, and a parameter table 336 concerningextended functions of object management.

[0053] Referring to FIG. 7, there are shown details of the partitionconfiguration field 333. In this field, a drive device ID 333B and astorage area 333C are defined in correspondence with a partition ID333A.

[0054] Referring to FIG. 8, there are shown details of the objectorganization parameter table 334.

[0055] In the object organization parameter table 334, availableparameter items 334A are contained before hand. Each current parametervalue 334C is indicated in correspondence with a partition ID 334B. Theavailable parameter items 334 for example, include the following; treestructure method, distributed tree structure method, indexing method,distributed indexing method, unused state, user-specified method, etc.

[0056] Referring to FIG. 9, there are shown details of the objectmanagement attribute parameter table 335.

[0057] The object management attribute parameter table 335 comprises aplurality of subtables 335-1, 335-2, and so forth, each corresponding toan individual partition ID. In each of these subtables, a parameternumber 335A, available parameter values 335C, and a current parametervalue 335D are indicated in correspondence with a selectable objectmanagement attribute item 335B.

[0058] Referring to FIG. 10, there are shown details of the parametertable 336 concerning extended functions of object management.

[0059] The extended function parameter table 336 comprises a pluralityof subtables 336-1, 336-2, and so forth, each corresponding to anindividual partition ID. In each of these subtables, a parameter number336A, available parameter values 336C, and a current parameter value336D are indicated in correspondence with a selectable extended functionitem 336B. In the example shown in FIG. 10, “designation of componentprogram” (P21), “component program” (P22), and “timing of execution”(P23) are indicated as the selectable extended function items.

[0060] In the memory 200, the component programs 340 are provided asshown in FIG. 3, which can be selected using the parameter P22. If acomponent program desired by the user is not found in the parametertable 336 used for indicating selectable component programs, the usermay add the desired component program into the memory 200 or the usermay specify a method for acquiring the desired component program to themagnetic disk storage device. Thus, any desired function can be added tothe object management program 350.

[0061] At the object management modification requester, the user selectsproper values of the available parameters mentioned above. Thus, theparameters in the management table 330 can be set to meet a user'sapplication program. According to current parameter values in themanagement table 330, the object management program 350 carries out dataread-write operations and component-program-based data processing whileselectively exchanging object organization, attributes and functionalityof component programs 340. Thus, in the magnetic disk storage device100, data management and data processing can be accomplished to meetuser's requirements.

[0062] For instance, in a data read operation, data read out of themagnetic disk 101 is temporarily stored into the buffer memory 360. Ifexecution of a special data processing based on any one of saidcomponent programs is designated on the read out data, the special dataprocessing is carried out in the course of data reading from themagnetic disk 101 to the buffer memory 360 or after data reading fromthe magnetic disk 101 to the buffer memory 360. Then, the data subjectedto the special data processing is transferred to the object managementmodification requester by the object management modification program320.

[0063] By way of contrast, in a data write operation, data received fromthe object management modification requester is temporarily stored intothe buffer memory 360 by the object management modification program 320.If execution of a special data processing based on any one of saidcomponent programs is designated on the data, the object managementprogram 350 carries out the special data processing on the data whilethe data is held in the buffer memory 360 or in the course of datatransfer from the buffer memory 360 to the magnetic disk 101.

[0064] Referring to FIG. 11, there is shown a time chart indicating mainsteps of the request program 420 for object management modification(hereinafter referred to simply as a request program) and the objectmanagement modification program 320 (hereinafter referred to simply as amodification program) in a process to modify the function of the objectmanagement program 350.

[0065] At the startup of the request program 420, if such data ascurrent parameter values 430 have already been set in the managementtable 430, it is allowed to carry out step 422 for requesting objectmanagement modification. If data necessary for object managementmodification have not yet been set in the management table 430, therequest program 420 sends a request 500 to authenticate the capabilityof object management modification to the modification program 320 (step421). The above-noted authentication request 500, for example, containsidentification information of the requester (user or source-of-requestequipment) and information concerning the type of modification desiredby the requester.

[0066] Upon receiving the authentication request 500, the modificationprogram 420 carries out an authentication routine (step 321). Inauthentication of the capability of object management modification, areference is made to the authentication table 370. In the authenticationtable 370, a condition of permission 370B is defined for each type ofmodification 370A. In execution of the authentication routine 321, it isjudged whether the requester satisfies the condition of permission 370Bor not. According to the result of judgment, a reply message 510indicating either rejection or permission of object managementmodification is returned to the request program 420 (step 322). In thereply message indicating permission of object management modification, apart or the whole of the management table 330 is contained as replydata.

[0067] When the request program 420 receives the reply messageindicating permission of object management modification, the requestprogram 420 sets up the reply data in the management table 430. Then,when the requester specifies a parameter for object managementmodification with reference to the management table 430, a requestmessage 400 for object management modification is generated and sent tothe modification program 320 (step 422).

[0068] In response to the modification request message 400, themodification program 320 carries out an object management modificationroutine (step 323). Then, the modification program 320 returns a replymessage 310 indicating the results of the updating of the managementtable 330 to the request program 420 (step 324). According to theresults of the updating of the management table 330 which are shown inthe results-of-processing field 413 of the reply message 310, therequest program 420 updates the management table 430 (step 423). Then,the above-described program session comes to an end.

[0069] Referring to FIG. 12, there is shown a detailed flowchart of therequest program 420.

[0070] In execution of the request program 420, it is checked whether ornot effective data is contained in the management table 430 (step 600).If the management table 430 contains effective data, step 610 is thencarried out. Alternatively, if the management table 430 contains noeffective data, a message 500 indicating the request to authenticate thecapability of object management modification is generated and sent tothe modification program 320 (step 601). Thereafter, the request program420 waits for arrival of the reply message 510 (step 602). Upon receiptof the reply message 510, its contents are checked (step 603). If thereply message 510 indicates rejection of object management modification,an error message is displayed (step 623) and execution of the requestprogram 420 comes to an end. If the reply message 510 indicatespermission of objet management modification, the reply data containedtherein is set up in the management table 430 (step 610), and thecontents of the management table 430 are displayed (step 610).

[0071] A judgment on user input is then made (step 612). If the user hasspecified that object management modification is not necessary,execution of the request program 420 comes to an end. Alternatively, ifthe user has specified that object management modification is necessary,an interface screen for generating a modification request message 400 isdisplayed and the request program 420 receives modification request datatherethrough (step 612). Upon completion of modification request datasetting, the request program 420 sends the modification request message400 to the modification program 320 (step 614) and then waits forarrival of the reply message 310 (step 620). In judgment on the contentsof the reply message 310 (step 621), if it is found that the request hasbeen accepted, the management table 430 is updated according to thereply message (step 622). Then, execution of the request program 420comes to an end. If it is found that the request has been rejected, anerror message is displayed (step 623).

[0072] Referring to FIG. 13, there is shown a detailed flowchart of themodification program 320.

[0073] If the modification program 320 receives the authenticationrequest message 500 (step 700), control is passed to an authenticationroutine 710 to be described below with particular reference to FIG. 14.If a message received by the modification program 320 is neither theauthentication request message 500 nor the object managementmodification request message 400 (step 720), a rejection message isreturned (step 723) and then execution of the modification program 320comes to an end. In a case where the object management modificationrequest message 400 is received, it is judged whether the requestedmodification is permissible or not (step 721). Unless it is permissible,a rejection message is returned (step 723). If it is permissible,control is passed to an object management modification routine 800 to bedescribed below with particular reference with FIG. 15.

[0074] Referring to FIG. 14, there is shown a detailed flowchart of theauthentication routine 710.

[0075] In execution of the authentication routine 710, theauthentication table 370 is referenced according to the type ofmodification indicated by the authentication request message 500, and itis judged whether or not requester identification information indicatedby the authentication request message 500 meets the condition ofpermission 370B. If the condition of permission 370B is met, theauthentication routine 710 returns a reply message which indicatesacceptance of the request, including the contents of the managementtable 330 (step 712). Otherwise, a reply message indicating rejection ofthe request is returned (step 713).

[0076] Referring to FIG. 15, there is shown a detailed flowchart of theobject management modification routine 800.

[0077] In execution of the object management modification routine 800,parameter values specified by the requester are read out successivelyfrom parameter field 404 of the request message 300 which is equivalentto the request message 400 (step 801). Then, the specified parametervalues are checked (step 802). If any specified parameter value is notpermissible, an error message is returned (step 808). If the specifiedparameter values are permissible, it is judged whether a user's privatecomponent program is specified or not (step 803). If any user's privatecomponent program is specified, it is then acquired (step 804). In casethat the specified user's private component program cannot be preparedon the memory 200 for use by the object management program 350 (step805), an error message is returned (step 808).

[0078] If no user's private component program is specified or if thespecified user's private component program is prepared on the memory200, the management table 350 is updated according to the first one ofthe specified parameter values (step 806). In case that the updating ofthe management table 350 fails (step 807), an error message is returned(step 808). After the management table 350 is updated, it is checkedwhether there is the next parameter value to be processed in the requestmessage (step 809). If the next parameter value is found, step 801 istaken again to repeat the sequence mentioned above. When all thespecified parameter values have been processed, a normal end message isreturned (step 810) and then execution of the object managementmodification routine 800 is terminated. Note that the normal end messagecontains management table data updated through the modificationprocessing described above.

[0079] Referring to FIG. 16, there is shown a format for an object I/Ocommand 440, which is a typical example of a file control command usedin execution of the object management program 350.

[0080] The object I/O command 440 comprises an operation code field 441for indicating the kind of command, a request ID field 442, and aparameter field 443. In the parameter field 443, there are provided anobject ID item 443A for indicating an object to be accessed forreading/writing, an offset item 443B for indicating an offset value fromthe top address of the object, and a data size item 443C. In the formatof the WRITE command, a data field for holding data to be written isprovided after the parameter field 443.

[0081] Referring to FIG. 17, there is shown a detailed flowchart of theobject management program 350.

[0082] In execution of the object management program 350, a partition IDcode is extracted from the object ID item 443A of a received object I/Ocommand 440 (step 901). The object ID item 443A contains a string ofnames in a hierarchical structure format with slant (/) characters fordelimitation. Where the object ID item 443A contains “/HOME/OBJl ” asshown in FIG. 16, the first name “/HOME” indicates a partition ID code.Using the partition ID code extracted at step 901, a reference is madeto the object organization table 334, shown in FIG. 8, which is a partof the management table 330. Thus, object organization in a partitionindicated by the partition ID code is recognized (step 902). In theexample shown in FIG. 8, object organization (file organization) in thepartition indicated by “/HOME” is arranged in a tree structure method.

[0083] Then, a judgment is formed on an operation code indicated in theoperation code field 441 of the object I/O command 440.

[0084] In a situation where the object I/O command 440 is a “READ”command (“YES” at step 903), data is read out of the magnetic disk 101through the disk controller 102 according to parameter values specifiedin the parameter field 443 of the object I/O command 440 (step 904). Atthis step, a reference is made to the object management table 355 whichdefines a correspondence relationship between object ID codes andphysical addresses on the magnetic disk 101. Through this operation, theobject ID code 443A of the object I/O command 440 is converted into aphysical address on the magnetic disk 101, thus providing a “READ”command that is acceptable by the disk controller 102. Note that, in theobject management table 355, the correspondence relationship betweenobject ID codes and on-disk physical addresses varies depending on thefile organization method of each object.

[0085] In the above-stated step 904, a reference is also made to thesubtable 335-1 concerning object management attribute parameters shownin FIG. 9 according to the partition ID code. Thus, for each object, aread operation is carried out based on a specified object managementattribute.

[0086] Then, a reference is made to the parameter table 336 concerningextended functions of object management shown in FIG. 10 according tothe partition ID code. If an extended function (component program) isindicated in the extended function parameter table 336 (step 905), dataread out onto the buffer memory 360 is processed using the extendedfunction (component program) (step 906). Then, the resultant data ofthis processing is sent to the requester by a reply message (step 930).

[0087] In a situation where the object I/O command 440 is a “WRITE”command (“YES” at step 910), a reference is made to the parameter table336 concerning extended functions of object management. If an extendedfunction (component program) is indicated in the extended functionparameter table 336 (“YES” at step 911), data held in the buffer memory360 is processed using the extended function (component program) (step912). Then, the resultant object data of this processing is written ontothe magnetic disk 101 through the disk controller 102 (step 913). Atthis step, a reference is made to the object management table 355 andthe subtable 335-1 concerning object management attribute parameters asin the case of execution of the “READ” command. Thus, based on aspecified object management attribute, a data write operation is carriedout at physical addresses corresponding to the object ID code.

[0088] In a situation where the file control command “OPEN”, “CLOSE”,“DELETE” or “CREATE” is given instead of the “READ” or “WRITE” command(“NO” at step 910), an operation specified by each command is carriedout (step 920).

[0089] Referring to FIG. 3, the following considers a situation wheredata read out onto the buffer memory 360 from the magnetic disk medium101 is transferred to the requester intactly: In a conventional magneticdisk storage device, a data block read out onto the buffer memory 360 isconverted into a data block form that can be transferred through thenetwork. It is therefore necessary to perform additional processing forcopying data from the buffer memory 360 to a second buffer area.

[0090] In such data transfer, according to the disk storage device ofthe present invention, a destination address of data transfer, data sizeand other transfer parameters are pre-specified as object managementattribute parameters 335, thereby making it possible to transferread-out data to the requester readily without the need to perform theabove-mentioned copying operation.

[0091] The object management modification request program 420 can beinstalled on the requester 130 manually. Further, for example, theobject management modification request program 420 may be downloadedfrom the magnetic disk storage device 100 to the requester 130 using anetwork access program such as a WEB browser.

[0092] The requester 130 on which the object management modificationrequest program 420 is run may also be the magnetic disk storage device100 on which the object management modification program 320 is run. Thatis to say, both the object management modification program 320 and theobject management modification request program 420 may be run on themagnetic disk storage device 100. In the modified arrangement mentionedabove, user data input from a remote terminal computer is supplied tothe object management modification request program 420 running on themagnetic disk storage device 100 through the use of a network accessprogram such as a WEB browser. In this case, as a requester ID code, anypredetermined value is assigned instead of a combination of an IPaddress and a port number.

[0093] While the present invention has been described in detail withrespect to specific embodiments in the magnetic disk storage device, itis to be understood that the invention is also applicable to a diskstorage device using any kind of storage medium other than the magneticdisk, such as a photomagnetic disk, optical disk and DVD.

What is claimed is:
 1. A disk storage device comprising: a disk storagemedium; a disk controller for accessing said disk storage medium toread/write data thereon; an interface for connecting said disk storagedevice to a network; object management means for converting a controlcommand containing an object identifier received through said interfaceinto a control command containing physical address information of saiddisk storage medium and for feeding the thus converted control commandto said disk controller; and object management modification means formodifying a function of said object management means in response to amodification request message received through said interface.
 2. A diskstorage device according to claim 1, further comprising: a managementtable which defines file organization for each partition defined in saiddisk storage medium; wherein said object management modification meansmodifies the file organization defined in said management table inresponse to said modification request message, and said objectmanagement means manages data stored on said disk storage mediumaccording to the file organization defined in said management table. 3.A disk storage device according to claim 2, wherein said managementtable defines data management attributes in correspondence with eachpartition arranged on said disk storage medium, said object managementmodification means modifies the data management attributes defined insaid management table in response to said modification request message,and said object management means controls data reading from said diskstorage medium and data writing thereto according to the data managementattributes defined in said management table.
 4. A disk storage deviceaccording to claim 2, wherein said management table contains definitionsof data processing to be executed in correspondence with each partitiondefined in said disk storage medium, said object management modificationmeans modifies the data processing definitions in said management tablein response to said modification request message, and said objectmanagement means carries out data processing on at least either of dataread out of said disk storage medium and data to be written onto saiddisk storage medium according to the data processing definitions in saidmanagement table.
 5. A disk storage device according to claim 4, furthercomprising: component programs corresponding to data processing definedin said management table; wherein said object management means carriesout said data processing with use of said component programs accordingto the definitions in said management table.
 6. A disk storage deviceaccording to claim 1, wherein said modification request message containsat least one of parameters concerning file organization, data managementattributes and data processing in correspondence with each partitionidentifier, and said object management modification means modifies atleast one of functions concerning file organization, data managementattributes and data processing, which are provided in said objectmanagement means, according to each parameter contained in saidmodification request message.
 7. A disk storage device comprising: adisk storage medium; a network interface; a disk controller having anobject management function for converting a high-level read/writecommand, which is received through said network interface and containingan object identifier specifying an access target, into a low-levelread/write command containing physical address information of said diskstorage medium to access to said disk storage medium; and objectmanagement modification means for modifying said object managementfunction in response to a modification request message received throughsaid network interface.